<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<input type="button" value="你点一下" onclick="gopay()">
</body>
</html>
<script>

function gopay(){
    window.location.href="http://mytest.bndvip.com/index.php?m=Api&c=Index&a=wexinpay_js";
}

</script>